import com.fasterxml.jackson.databind.ObjectMapper;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
@WebServlet("/userInfo")
public class UserInfoServlet extends HttpServlet {
    private ObjectMapper objectMapper = new ObjectMapper();
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String blogId = req.getParameter("blogId");
        if(blogId==null){
            getUserInfoFromSession(req,resp);
        }else{
            getUserInfoFromDB(req,resp,Integer.parseInt(blogId));
        }

    }
    private void getUserInfoFromDB(HttpServletRequest req,HttpServletResponse resp,int blogId) throws IOException {
        //1.现根据blogId查询blog 对象，获取到userId

        BlogDao blogDao = new BlogDao();
        Blog blog = blogDao.selectOne(blogId);
        if (blog==null) {
            //如果参数传来的这个blogId是瞎写的，数据库里没有
            resp.setStatus(404);
            resp.setContentType("text/html;charset=utf8");
            resp.getWriter().write("blogId不存在");
            return;
        }
        //2.根据userId查询对应user对象
        UserDao userDao = new UserDao();
        User user = userDao.selectById(blog.getUserId());
        if (user==null) {
            resp.setStatus(404);
            resp.setContentType("text/html;charset=utf8");
            resp.getWriter().write("blogId不存在");
            return;
        }
        //3.把user对象返回给浏览器
        user.setPassword("");
        resp.setContentType("application/json;charset=utf8");
        resp.getWriter().write(objectMapper.writeValueAsString(user));
    }
    private void getUserInfoFromSession(HttpServletRequest req,HttpServletResponse resp) throws IOException {
        HttpSession session = req.getSession(false);
        if (session == null) {
            resp.setStatus(403);
            resp.setContentType("text/html;charset=utf8");
            resp.getWriter().write("当前未登录");
            return;
        }
        User user = (User) session.getAttribute("user");
        if(user==null){
            resp.setStatus(403);
            resp.setContentType("text/html;charset=utf8");
            resp.getWriter().write("当前未登录");
            return;
        }
        user.setPassword("");
        resp.setContentType("application/json;charset=utf8");
        resp.getWriter().write(objectMapper.writeValueAsString(user));
    }

}
